JPH02195575A - Tape recording/reproducing device - Google Patents

Abstract

PURPOSE:To quickly record and reproduce the data by referring to a 1st table for detection of logical block addresses and a 2nd table for detection of physical block address respectively. CONSTITUTION:The memory means 40 and 41 are prepared to write a 1st table and a 2nd table respectively. The 1st table is connected to a data recording/ reproducing means 22 and detects the logical block address signals written via the physical block addresses. The 2nd table is also connected to the means 22 and detects the physical block addresses written via a data block including the logical block address signals received from the logical block addresses. Thus it is possible to know an idle physical block address closest to the physical block address where the signal conversion heads 3 and 4 are presently included by reference to the 1st table. While the physical block address corresponding to the logical block address signal to be read out is known by reference to the 2nd table. As a result, the data can be quickly recorded and reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a computer or similar device for recording data on a recording medium tape and reproducing data from a recording medium tape. The present invention relates to a tape recording/playback device.

[Prior Art and Problems to be Solved by the Invention] Magnetic disk recording and reproducing devices and magnetic tape recording and reproducing devices are mainly used as storage devices for computers or similar devices. A magnetic disk recording/reproducing apparatus includes a magnetic disk having a large number of concentric tracks, means for rotating the disk, a signal converting head, and means for moving the signal converting head in the radial direction of the disk. Since the signal conversion head can quickly move to any desired track, data can be rapidly recorded and reproduced on a desired track.

Magnetic tape recording and reproducing apparatuses can be roughly divided into fixed head type magnetic tape recording and reproducing apparatuses and rotating head type magnetic tape recording and reproducing apparatuses. In the former fixed head type magnetic tape recording/reproducing device, an extremely long track is formed along the length of the tape from the beginning of the tape to the end of the tape. Therefore, in a fixed head magnetic tape recording/reproducing device,
Any track position! Since it is difficult to record data on a tape, data is written sequentially from the beginning of the tape to the end of the tape by sequential access.

The latter rotary magnetic tape recording and reproducing device is mainly used for VTR (
The device is configured to write data using a video tape recorder) or a DAT (digital audio tape recorder). In the case of DAT, a large number of tracks are formed that have a constant inclination angle with respect to the longitudinal direction of the magnetic tape. Then, a track number is written in this track, and the track can be searched based on this number. Therefore, it is possible to write data to or read data from any track by direct access, similar to a magnetic disk recording/reproducing device. However, even with a rotary head type magnetic tape recording/reproducing apparatus, the access time, that is, the seek time, is significantly longer than that of a magnetic disk recording/reproducing apparatus.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a tape recording and reproducing apparatus that can shorten access time.

[Means for Solving the Problems] To achieve the above object, the present invention provides a tape running means for running a 9Jr medium tape having a large number of physical block addresses, and a relative scanning method between the recording medium tape and the recording medium tape. a signal conversion head for recording and reproducing data by movement; a data write command signal input means for accepting a data write command signal when writing data on the recording medium tape; a data block input means for accepting data as a plurality of data blocks; and a write logical block for accepting a write logical block address signal determined to correspond to the data block to be written accepted by the data block input means. address signal input means; data read command signal input means for accepting a data read command signal when reading data from the recording medium tape;
reading logical block address signal input means to which a logical block address signal corresponding to the data block to be read is given when reading the data block from the recording medium tape; and data for outputting the data read from the recording medium tape. output means, the signal conversion head, the tape running means, the data write command signal input means, the data block input means, the write logic block address signal input means, the data read command signal input means, and the read logic. connected to a block address signal input means and the data output means, in response to the data write command signal, the plurality of data blocks, and the plurality of logical block address signals corresponding to the plurality of data blocks; The signal conversion head and the recording medium are configured to send the plurality of data blocks and respective logical block address signals to the signal conversion head, and to write the data blocks and the logical block address signals to desired physical block addresses. The physical block address corresponding to the read logical block address signal is configured to control the relative positional relationship with the tape, and in response to the data read command signal and the read logical block address signal. a data recording and reproducing means configured to position the signal converting head, read a data block corresponding to a read logical block address signal from the recording medium tape by the signal converting head, and send the read data block to the data output means; , is connected to the data recording and reproducing means, and is written with a first table created so that the logical block address signal written here can be determined from the physical block address, and and memory means in which a second table is written, which is created so that the physical block address in which the data block having the logical block address signal is written can be determined from the logical block address signal. This relates to a tape recording and reproducing device.

Note that the physical block address in the present invention means a physically determined location on the recording iX external tape where one or more data blocks can be written. Further, a data block means a collection of data of a fixed amount of bytes, such as 32,768 bytes or 16,384 bytes, and can also be called a logical block. A signal for identifying this data block (logical block) is called a logical block address signal in the present invention.

[Operation] By referring to the first table in the present invention, it is possible to easily know the address of an empty physical block to which no data block has been written. Therefore, the nearest empty physical block address can be obtained from the physical block address where the signal conversion head is currently located. This makes it possible to quickly write a data block to an empty physical block address. Furthermore, since data blocks can be written to empty block addresses, it is no longer necessary to write data blocks sequentially from the beginning to the end of the tape. As a result, writing of a certain data block is finished,
If the next data block to be written is not input continuously, the running of the magnetic tape can be continued without being stopped, thereby creating an empty physical block address. Continuing the running of magnetic data means that writing can be started quickly when the next data block to be written is input.

The second table is used when reading a desired data block from the recording medium tape. When a logical block address signal to be read from the host device is given,
The physical block address corresponding to the logical block address signal to be read is known by referring to the second table. Since the data block corresponding to the #la physical block address signal to be read is written in this physical block address, reproduction of the desired data block can be quickly achieved.

[Embodiment] Next, a magnetic tape recording/reproducing apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7.

The magnetic data recording/reproducing apparatus 1 shown surrounded by a dotted line in FIG. 1 has a pair of magnetic heads 3.4 for signal conversion that rotate together with the drum 2. A pair of magnetic heads 3.4 is 180
The magnetic tape 5 is arranged at intervals of 50 degrees and alternately faces the magnetic tape 5 to record or reproduce data. The drum 2 is rotated by a motor 6 coupled thereto.

The magnetic tape 5 is a pair of reels 8 in a tape cassette 7.
．． 9 runs between each other. The tape running mechanism for running the magnetic tape 5 includes motors 1o and 11 for driving a pair of inner reels 8.9, a capstan 12, a pinch roller 13, and a capstan motor 14. It has the same structure as the well-known DAT. The magnetic tape 5 is wound around the drum 2 at an angle of about 90 degrees,
Moreover, it is wound so as to be oblique to the rotation plane of the pair of magnetic heads 3.4. Therefore, the magnetic head 3
．． 4 is the same as the well-known DAT, and the magnetic head 3.4 alternately scans tracks 15 inclined with respect to the longitudinal direction of the magnetic tape 5, as shown in FIG. .

Each track 15 of the magnetic tape 5 has a PCM area 1111116 in the center as shown in FIG.
17 and a sub code area 18. The PCM area 16 is an area for recording data and has a capacity of 23,040 bits. Each ATF area 1 is double provided to prevent dropout.
Signals necessary for controlling the magnetic head 3.4 to follow the track 15 are recorded in 7, respectively. Double subcode area 1! ! 18, a time code and a signal of the song are recorded to be used as tape position information.

Returning to the description of FIG. 1, each motor 6.10.11.14 is connected to a scan control circuit 19. Scan control circuit 19
The motors 6, 10, 11, 14 are controlled so that the relative scanning speed between the magnetic head 3.4 and the magnetic tape 5 becomes a predetermined value.
At the same time, the function of positioning the magnetic head 3.4 at a desired position on the magnetic tape 5, that is, seek (5 seek
) has a function.

A pair of magnetic heads 3.4 are rotary transformers 20.21
It is connected to the recording/reproducing circuit 22 via. The recording/reproducing circuit 22 has the same configuration as the recording/reproducing circuit in a well-known DAT.
In this embodiment, a stereo signal obtained by converting an audio signal into a digital signal is input and output, but in this embodiment, instead of the stereo signal, data in a computer or similar system is input and output.

Magnetic tape recording/reproducing device 1 as a storage device! A host computer 23 used as a host computer 23 includes a CPU, a magnetic disk storage device, etc.
A data write command signal to write data to, data to be written, a logical address signal for identifying this data (logical block address signal for writing),
A data read command signal and an address signal (read logical block address signal) indicating the data to be read are generated. In this example, one data block is
It is determined to be 32,768 bytes. 1 byte is 8 bits. This 32,768-byte data block is assigned a logical block address, that is, a data block number. Since the logical block address signal is recorded on the magnetic tape 5 together with the data block (logical block), the host computer 23 can perform the following operations without providing information indicating the physical position of the magnetic tape 5 to the magnetic tape recording/reproducing apparatus 1. The target data block can be read. That is, when reproducing data, the host computer 23 can read a target data block by generating a logical block address signal instead of information indicating the physical position of the magnetic tape 5. Therefore, the magnetic tape recording/reproducing apparatus 1 of this embodiment conforms to the ANST standard of the United States.
X3゜131-1986 “SIMall Comp
uter System Interface".

A controller 25 connected to the host computer 23 via a bus 24 is for controlling the magnetic tape recording/reproducing apparatus 1 and has a function equivalent to an interface.

The interface 26 between the controller 25 and the magnetic tape recording/reproducing device 1 includes a data block input line 27, a data block output line 28, a data write command signal line 29, a data read command signal line 30, a write logical block address signal line 31, They are connected by a read logical block address signal line 32. There are actually more lines for exchanging signals, but these are omitted.

The data block input line 27 is connected to an input buffer 33 via an interface 26. Output buffer 34 is connected to data block output line 28 via interface 26.

In order to record logical block address signals in addition to data blocks on the magnetic tape 5, a multiplexer (iult) is installed between the input buffer 33 and the recording/reproducing circuit F#I22.
iplexer) 35 is provided.

This multiplexer 35 is provided with a logical block address signal from line 36. As a result, the multiplexer 35 outputs the data block plus the logical block address signal.

A de-multiplexer provided between the recording/reproducing circuit 22 and the output buffer 34
37 extracts a data block from the output obtained from the magnetic head 3.4 during reproduction and sends it to the output buffer 34;
In addition, the logical block address, physical block address, etc. are extracted and the microcomputer 39 is connected to the line 38.
It is given to

A microcomputer (microprocessor) 39 including CPtJ, RAM, and ROM has an interface 26.
A data write command signal line 29, a data read command signal line 30, a logical block address signal line 31 for writing, and a logical block address signal line 32 for reading are connected through the first and second tables. RAM (Random Access Memory) 40.41 is also connected.

The microcomputer 39 is for executing various controls according to a control program written in the ROM, for example, scanning control signals for determining the positional relationship between the magnetic head 3.4 and the magnetic tape 5. It has the function of providing one circuit.

[Format of magnetic tape] FIG. 4 shows each track 15 of the magnetic tape 5 shown in FIG.
PCM areas 16 are connected in series to equivalently represent one track of the magnetic tape. All PCMs in the effective recording area of this magnetic tape 5 in the section from BOT (tape start @) to EOT (tape end)
The total number of frames in area 16 is 239,995. However, one frame is 5760 bytes. In this embodiment, one physical block address is 7 frames (40,320 bytes), so the magnetic tape 5 has 34,285 physical block addresses.

As shown in FIG. 4, the magnetic tape 5 has a gap 51 of 2800 frames and a diagnostic area 52.84 of 28 frames.
The frame tape management area 53, the 378 frame gap 54, the 229376 frame user data area 55, the 378 frame gap 56, the 84 frame spare tape management area 57, and the 6867 frame gap 58 from BOT. E, with I(f towards OT).

Each gap 51.54.56.58 has another area 52.5
The 6 diagnostic area 52 provided to protect the magnetic tape 5 is an area for diagnosing whether or not the magnetic tape 5 can be used for normal recording and reproduction. The tape management area 53 is an area in which the first table of the RAM 40 shown in FIG. 1 and other various information necessary for tape management are written. The user data area 55 is an area in which data blocks given from the host computer 23 are written. The spare tape management area 57 is the tape management area 53
This is a spare area for writing tape management information such as the first table when it is not possible to write tape management information such as the first table in the tape management area 53 for some reason.

[Physical Block Format] As shown in FIG. 5, the physical block format consists of seven frames (40,320 bytes), and has a D (identification) area 61, a data area 62, and a gap 63. ■D@1!1iI61 is 17
92 bytes are allocated. The message ID head area 61 has a 2-byte physical block address area 61a, a 2-byte logical block address area 61b, and a 1788-byte area 61c in which various other information is written.

The address signal of this physical block is written in the physical block address area 61a. A logical address signal for identifying a data block written in the data area 62 is written in the logical block address area 61b. The data area 62 to which 32,768 bytes are allocated is an area in which data blocks (logical blocks) given from the host computer 23 are written.

In this embodiment, one data block corresponds to one physical block. Also, one data block is 3
It consists of 2768 bytes. A gap 63 to which 5760 bytes are allocated is an area for partitioning physical blocks from each other.

[First Table The first table written in the RAM 40 in FIG.
As shown in Figure 6, it is a comparison table of physical block addresses and logical block addresses based on the physical block address, and 32768 physical block addresses from 0 to 32767 are arranged in order, and each Block address The block address is designed so that it is possible to know whether or not a data block has been written, and also to be able to know the address of the data block (logical block address). The contents of this first table are updated every time a data block is written or rewritten on the magnetic tape 5.

[Second Table] The second table written in the RAM 41 stores data block addresses (logical block addresses) that can be physically written in correspondence with the 32,768 physical blocks included in the magnetic tape 5. This is a comparison table of logical block addresses and physical block addresses based on a standard.

That is, the second table is created so that it can be immediately known to which physical block address a data block assigned a certain logical block address is written. This second table is created based on the first table shown in FIG.

[Operation] The magnetic tape recording/reproducing device 1 is operated by a host computer 23.
When a format command is received from , physical block addresses are allocated to perform the tape format and physical block format shown in FIGS. 4 and 5.

When the power is turned on and the tape cassette 7 containing the magnetic tape 5 on which data has been written is loaded into the tape transport mechanism, the playback mode is automatically set in response to this, and the tape management of the magnetic tape 5 is performed. The first table written in area 53 is read out and stored in RAM 40, and the second table is determined from the first table and stored in RAM 41.

When a data write command signal and a write logical block address are applied to the three microcomputers through lines 29 and 31, and a data block corresponding to the write logical block address is applied from line 27 to the input buffer 33, the microcomputer 39 is the RA according to the control program written in the ROM.
M40's first table is referred to to find the nearest empty physical block address from the current position of the magnetic head 3.4 on the magnetic tape 5. Note that the current position of the magnetic head 3.4 on the magnetic tape 5 is is microcomputer 3
9 RAM.

The microcomputer 39 provides the scan control circuit 19 with a control signal for positioning the magnetic head 3.4 to the nearest vacant physical block address from the current position. As a result, when the desired physical block address of the magnetic tape 5 faces the magnetic head 3 or 4, the logical block address is given from the microcomputer 39 to the magnetic head 3.4 via the multiplexer 35 and the recording/reproducing port #122. Logical block address area 61b shown in FIG.
is written in. Subsequently, the data block in the input buffer 33 is applied to the magnetic head 3.4 via the multiplexer 35 and the recording/reproducing circuit 22, and is written into the data area 62 in FIG. When data blocks are continuously input to the magnetic tape recording/reproducing apparatus 1 and there are consecutive vacant physical block addresses, the data blocks are written sequentially. In addition, if data blocks are input intermittently and there are continuous empty physical block addresses, the magnetic tape 5 continues to run despite the interruption of data block input, and the data blocks are input again. If the magnetic tape 5 continues to run in this way, data blocks can be written quickly. However, the interruption time of data block input is measured, and when this becomes longer than a predetermined value, tape running is stopped and the magnetic tape 5 is placed in a recording standby state. If this is continued, an empty physical block address will occur, but based on the first table, this empty physical block address can be known and a data block can be written there later. Note that if there is no free physical block address, the data is written to a physical block address to which a data block having the same physical block address has been written.

When writing of the data block to the physical block address is completed, this relationship is registered in the first table of the RAM 40. This relationship is also ffied to the second table of the RAM 41. When all data blocks have been written and a tape running stop command (unload command) is given, the microcomputer 39 responds by writing the first table in the RAM 40 to the tape management area 53 in FIG. After that, the running of the tape 5 is stopped.

In the data reproduction mode, the microcomputer 39
When the microcomputer 39 receives a data read command signal from line 30 and a read logical block address signal from line 32, the microcomputer 39
A physical block address corresponding to the read logical block address signal is obtained from the second table of 41, and a control signal for running the magnetic tape 5 is scanned so that the magnetic tape 3 or 4 is opposed to this physical block address. It is given to the control circuit 19. Thereafter, the physical block address to which the data block having the read logical block address signal has been written is reproduced, and the target data block is reproduced. The data reproduced by the magnetic head 3.4 is sent to the output line 28 via the recording/reproducing circuit 22, the demultiplexer 37, the output buffer 34, and the interface 26.

When a read logical block address signal is given, the physical block address is determined by referring to the second table in FIG. 7 rather than the first table shown in FIG. 6 to determine the physical block address. The learning time is short, so using the second table makes it possible to read data quickly. Note that the ID signal recorded in the physical block address, the ATF signal in the ATF area 17 in FIG. 3, and the subcode signal in the subcode area 18 are extracted by the demultiplexer 37 and sent to the microcomputer 39.

[Modifications] The present invention is not limited to the above-described embodiments, and, for example, the following modifications are possible.

(1) As shown in FIG. 8, a cache buffer (Cache b) consisting of RAM is provided after the output buffer 34
buffer) 70 may be provided to store a plurality of data blocks that are frequently accessed (used frequently).This allows the data block specified by the logical block address to be read from the magnetic tape 5, It becomes possible to read from the cache buffer 70 and output it.

(2) In this embodiment, one physical block address has one
A data block with two logical block addresses is written, but the number of bytes in the data block is reduced to one.
A plurality of data blocks may be written to one physical block address.

(3) RAM40.41 for the first and second tables
Instead of providing them independently, a RAM built in the microcomputer 39 may be used, or one RAM may be shared by the first and second tables.

(4) Instead of giving the formatting command from the host computer 23, a switch for giving the formatting command may be provided in the magnetic tape recording/reproducing apparatus 1, and the formatting command may be created by this switch.

(5) As shown in FIG. 2, a rotary head type magnetic tape recording/reproducing device 1 in which a diagonal scanning track 15 is formed,
Although the present invention is suitable for rapid data recording and reproduction, it is not limited thereto, and the present invention can also be applied to a magnetic chip recording and reproducing device in which tracks are formed along the longitudinal direction of a magnetic tape. can.

[Effects of the Invention] As is clear from the above, according to the present invention, 1. It becomes possible to quickly record and reproduce data by referring to the first and second tables.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the principle of a magnetic tape recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a plan view showing the track form on the magnetic tape of FIG. 1, and FIG. 4 is a diagram showing the track format when the PCM area of multiple tracks of the magnetic tape is considered as one track. FIG. 5 is a diagram showing the physical block format. FIG. 6 is a diagram showing an example of the first table, FIG. 7 is a diagram showing an example of the second table, and FIG. 8 is a block diagram showing a modified example. DESCRIPTION OF SYMBOLS 1... Magnetic tape recording/reproducing device, 3.4... Magnetic head, 5... Magnetic tape, 19... Scanning control circuit,
27... Data block line, 28... Data block output line, 29... Data write command signal line, 30... Data read command signal line, 31... Logical block address signal line for writing. 32...Logic block address signal line for reading, 39...Microcomputer, 4o...RAM for first table, 41...R for second table
A.M.

Claims (1)

[Claims] [1] A tape running means for running a recording medium tape having a large number of physical block addresses, and a signal for recording and reproducing data by a relative scanning motion with the recording medium tape. a conversion head; a data write command signal input means for accepting a data write command signal when writing data on the recording medium tape; and a data block for accepting data to be written on the recording medium tape as a plurality of data blocks. input means; write logical block address signal input means for accepting a write logical block address signal determined to correspond to the data block to be written accepted by the data block input means; and data from the recording medium tape. a data read command signal input means for accepting a data read command signal when reading the data block; and a read logic for receiving a logical block address signal corresponding to the data block to be read when reading the data block from the recording medium tape. block address signal input means, data output means for outputting data read from the recording medium tape, the signal conversion head, the tape running means, the data write command signal input means, the data block input means, and the It is connected to the write logical block address signal input means, the data read command signal input means, the read logical block address signal input means, and the data output means, and is connected to the data write command signal and the plurality of data blocks. In response to the plurality of logical block address signals corresponding to the plurality of data blocks, the plurality of data blocks and respective logical block address signals are sent to the signal conversion head, and the plurality of data blocks and the respective logical block address signals are sent to the signal conversion head, and the It is configured to control the relative positional relationship between the signal conversion head and the recording medium tape so as to write the data block and the logical block address signal, and to write the data block address signal and the read logical block address signal. position the signal converting head at the physical block address corresponding to the read logical block address signal, and read the data block corresponding to the logical block address signal from the recording medium tape by the signal converting head. data recording and reproducing means configured to read out and send to the data output means; and the logical block address connected to the data recording and reproducing means and written here from the physical block address. A first table is written so that the signal can be determined, and the first table is created so that the physical block address in which the data block having the logical block address signal is written can be determined from the logical block address signal. 1. A tape recording and reproducing apparatus comprising: memory means in which a second table is written. [2] The signal conversion head is a rotating magnetic head, and the tape running mechanism is configured to rotate with respect to the rotation plane of the rotating magnetic head so that a large number of scanning tracks having angles with respect to the longitudinal direction of the recording medium tape are generated. 2. The tape recording and reproducing apparatus according to claim 1, wherein the recording medium tape is run at an angle. [3] The data recording and reproducing means includes: a scanning control circuit connected to the tape running means to control the relative positional relationship between the recording medium tape and the signal conversion head; and the data block input means. an input buffer connected to the input buffer, the data write command signal input means, the write logical block address signal input means, the data read command signal input means, the read logical block address signal input means, the memory means, and the scan physical blocks connected to the control circuit and into which the data block to be written is written based on the data write command signal, a logical block address signal corresponding to the data block to be written, and the first table of the memory means; determining an address and providing a signal for positioning the signal converting head at the determined physical block address to the scanning control circuit; A physical block address corresponding to the read logical block address signal is determined based on the second table, and a signal for positioning the signal conversion head at the determined physical block address is provided to the scanning control circuit. an input buffer connected to the data block input means; and an input buffer connected to the input buffer and the processing means for inputting the data block and the logical block address signal of the data block on a common time axis. 2. The tape recording device according to claim 1, further comprising: a multiplexer disposed in the signal converting head for sending the signal to the signal converting head; and an output buffer connected between the signal converting head and the data output means. playback device. [4] The tape recording and reproducing apparatus according to claim 3, further comprising a cache buffer connected to the data output means. [5] The data recording and reproducing means further determines an empty physical block address (data block non-recording physical block address) closest to the physical block address of the recording medium tape where the signal conversion head is currently located. 2. The tape recording and reproducing apparatus according to claim 1, wherein the tape recording and reproducing apparatus is configured as follows.